US7442515B2 - Apparatus and methods for binding molecules and cells - Google Patents

Apparatus and methods for binding molecules and cells Download PDF

Info

Publication number
US7442515B2
US7442515B2 US10/630,235 US63023503A US7442515B2 US 7442515 B2 US7442515 B2 US 7442515B2 US 63023503 A US63023503 A US 63023503A US 7442515 B2 US7442515 B2 US 7442515B2
Authority
US
United States
Prior art keywords
temperature
poly
responsive
population
responsive material
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related, expires
Application number
US10/630,235
Other languages
English (en)
Other versions
US20040053334A1 (en
Inventor
Buddy D. Ratner
Xuanhong Cheng
Karl Bohringer
Yanbing Wang
Yael Hanein
Ashutosh Shastry
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
University of Washington
Original Assignee
University of Washington
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by University of Washington filed Critical University of Washington
Priority to US10/630,235 priority Critical patent/US7442515B2/en
Assigned to WASHINGTON, UNIVERSITY OF reassignment WASHINGTON, UNIVERSITY OF ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: WANG, YANBING, HANEIN, YAEL, CHENG, XUANHONG, SHASTRY, ASHUTOSH, BOHRINGER, KARL, RATNER, BUDDY D.
Publication of US20040053334A1 publication Critical patent/US20040053334A1/en
Application granted granted Critical
Publication of US7442515B2 publication Critical patent/US7442515B2/en
Adjusted expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12M—APPARATUS FOR ENZYMOLOGY OR MICROBIOLOGY; APPARATUS FOR CULTURING MICROORGANISMS FOR PRODUCING BIOMASS, FOR GROWING CELLS OR FOR OBTAINING FERMENTATION OR METABOLIC PRODUCTS, i.e. BIOREACTORS OR FERMENTERS
    • C12M25/00—Means for supporting, enclosing or fixing the microorganisms, e.g. immunocoatings
    • C12M25/06—Plates; Walls; Drawers; Multilayer plates
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12M—APPARATUS FOR ENZYMOLOGY OR MICROBIOLOGY; APPARATUS FOR CULTURING MICROORGANISMS FOR PRODUCING BIOMASS, FOR GROWING CELLS OR FOR OBTAINING FERMENTATION OR METABOLIC PRODUCTS, i.e. BIOREACTORS OR FERMENTERS
    • C12M23/00—Constructional details, e.g. recesses, hinges
    • C12M23/20—Material Coatings
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12M—APPARATUS FOR ENZYMOLOGY OR MICROBIOLOGY; APPARATUS FOR CULTURING MICROORGANISMS FOR PRODUCING BIOMASS, FOR GROWING CELLS OR FOR OBTAINING FERMENTATION OR METABOLIC PRODUCTS, i.e. BIOREACTORS OR FERMENTERS
    • C12M25/00—Means for supporting, enclosing or fixing the microorganisms, e.g. immunocoatings
    • C12M25/02—Membranes; Filters
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
    • G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
    • G01N33/53—Immunoassay; Biospecific binding assay; Materials therefor
    • G01N33/543—Immunoassay; Biospecific binding assay; Materials therefor with an insoluble carrier for immobilising immunochemicals
    • G01N33/544—Immunoassay; Biospecific binding assay; Materials therefor with an insoluble carrier for immobilising immunochemicals the carrier being organic
    • G01N33/545—Synthetic resin

Definitions

  • the present invention relates to devices for selectively and/or locally binding cells or proteins to a surface, such as silicon chips that include a temperature-responsive layer that binds cells or proteins when heated, and to methods for measuring the interaction between proteins and/or living cells in vitro.
  • microchips e.g., pieces of silicon, or glass, typically having dimensions of no more than a few centimeters
  • the living cells are contacted with a candidate drug, and the response of the cell to the candidate drug is measured, thereby indicating whether the candidate drug may be effective to modulate a biochemical or physiological pathway implicated in a disease state.
  • the small size of the microchips permits many candidate drugs to be simultaneously screened.
  • immunoassays can be conducted using microchips that include antibody molecules attached to a microchip surface.
  • the microchip is contacted with a fluid sample taken from an animal subject (e.g., a human being), and binding of the cognate antigen to the antibody molecules immobilized on the microchip is measured.
  • a fluid sample e.g., human blood sample
  • a fluid sample e.g., human blood sample
  • the fluid sample is then washed away, and the microchip is contacted with fluorescently-labelled antibody B that binds to a different portion of antigen A than does antibody A.
  • the amount of fluorescent antibody B bound to antigen A is measured, thereby permitting calculation of the amount of antigen A bound to the microchip.
  • the amount of antigen A present in the fluid sample can therefore be calculated.
  • microchips, and other devices that selectively bind living cells, proteins, or other molecules, to one, or more, specific locations on a surface of the device, and methods for making such devices.
  • the devices can bind most, or all, types of living cells and/or proteins.
  • the present invention provides devices for binding cells or molecules, wherein each device includes (a) a body defining a first surface and a second surface that is located opposite to the first surface; (b) a heater disposed upon the first surface; and (c) a temperature-responsive layer disposed upon the second surface, wherein the temperature-responsive layer comprises a temperature-responsive material that can exist in a first state that binds molecules or living cells, and can exist in a second state that binds substantially less molecules or living cells than the first state, and wherein the temperature-responsive material is reversibly convertible to the first state from the second state in response to an effective amount of thermal energy.
  • the present invention provides methods for binding molecules or living cells to a temperature-responsive material, wherein the methods each include the steps of contacting a temperature-responsive material with a population of molecules or a population of living cells, wherein: (a) the temperature-responsive material can exist in a first state that binds molecules or living cells, and can exist in a second state that binds substantially less molecules or living cells than the first state, and wherein the temperature-responsive material is reversibly convertible to the first state from the second state in response to an effective amount of thermal energy; and (b) the temperature-responsive material exists in the first state when the temperature-responsive material is contacted with the population of molecules or living cells, thereby effecting binding of the molecules or living cells to the temperature-responsive material.
  • the present invention provides methods for binding more than one type of molecule or more than one type of living cell to a temperature-responsive material, wherein the methods each include the steps of: (a) contacting a temperature-responsive material with a first type of molecules or a first type of living cells, wherein the temperature-responsive material is attached to a device body wherein the device body defines a first surface and a second surface that is located opposite the first surface, wherein a first population of heaters and a second population of heaters are disposed upon the first surface, and wherein the temperature-responsive material forms a temperature-responsive layer on the second surface; (b) activating the first population of heaters to heat a first population of temperature-responsive layer portions, located on the second surface opposite the first population of heaters, so that the first type of molecules or the first type of living cells binds to the first population of temperature-responsive layer portions, said activation occurring before or during the contacting of the temperature-responsive material with the first type of molecules or the first type of living cells; (c) removing any of
  • the present invention provides methods for measuring a response of a population of living cells to an agent, wherein the methods of this aspect of the invention each include the steps of contacting a population of living cells with an agent and measuring a response of the living cells to the agent.
  • the living cells are attached to a temperature-responsive material that can exist in a first state that binds living cells, and can exist in a second state that binds substantially less living cells than the first state, wherein the temperature-responsive material is reversibly convertible to the first state from the second state in response to an effective amount of thermal energy.
  • the temperature-responsive material exists in the first state while the living cells are contacted with the agent.
  • the present invention provides methods for observing the binding of members of a binding pair, wherein the methods each include the steps of contacting a first member of a binding pair with a second member of a binding pair and observing the binding of the first member of the binding pair with the second member of the binding pair.
  • the first member of the binding pair is attached to a temperature-responsive material that can exist in a first state that binds the first member of the binding pair, and can exist in a second state that binds substantially less first member of the binding pair than the first state, wherein the temperature-responsive material is reversibly convertible to the first state from the second state in response to an effective amount of thermal energy.
  • the temperature-responsive material exists in the first state while the first member of the binding pair is contacted with the second member of the binding pair.
  • FIG. 1 shows a perspective view of a representative device of the present invention viewed in the direction of a first surface.
  • FIG. 2 shows a perspective view of the device shown in FIG. 1 viewed in the direction of a second surface located opposite the first surface, and showing a partially cut-away temperature-responsive layer.
  • FIG. 3 shows a side view of the device shown in FIGS. 1 and 2 .
  • FIG. 4 shows a plan view of another representative device of the present invention that includes six heaters.
  • FIG. 5 shows a plan view of the device shown in FIG. 4 (viewed in the direction of the surface opposite the surface shown in FIG. 4 ).
  • the present invention provides devices for binding cells or molecules, wherein each device includes (a) a body defining a first surface and a second surface that is located opposite to the first surface; (b) a heater disposed upon the first surface; and (c) a temperature-responsive layer disposed upon the second surface, wherein the temperature-responsive layer comprises a temperature-responsive material that can exist in a first state that binds molecules or living cells, and can exist in a second state that binds substantially less molecules or living cells than the first state, and wherein the temperature-responsive material is reversibly convertible to the first state from the second state in response to an effective amount of thermal energy.
  • a second state that binds substantially less molecules or living cells than the first state means that the second state of a temperature responsive material binds less than 15% of the molecules, or living cells, bound by the first state of the same temperature responsive material, under the same binding conditions and given the same amount of time for binding to occur. In some embodiments, the second state of a temperature responsive material binds less than 10% of the molecules or living cells bound by the first state of the same temperature responsive material, under the same binding conditions and given the same amount of time for binding to occur. In some embodiments, the second state of a temperature responsive material binds less than 5% of the molecules or living cells bound by the first state of the same temperature responsive material, under the same binding conditions and given the same amount of time for binding to occur.
  • FIG. 1 shows a perspective view of a representative device 10 of the present invention.
  • Device 10 includes a body 12 defining a first surface 14 , a second surface 16 located opposite to first surface 14 , a first face 18 , a second face 20 , a first end 22 and a second end 24 .
  • a heater 26 is disposed on first surface 14
  • a temperature-responsive layer 28 is disposed on second surface 16 .
  • FIG. 2 shows a perspective view of second surface 16 of device 10 with temperature-responsive layer 28 partially cut away to more clearly show second surface 16 .
  • Heater 26 includes heating element 30 .
  • FIG. 3 shows a side view (looking at first face 18 ) of representative device 10 shown in FIGS. 1 and 2 .
  • heating element 30 In operation, application of an electrical current, or electrical potential, to heating element 30 generates heat that is transferred to a portion 32 of temperature-responsive layer 28 that is located opposite heater 26 (in FIG. 3 the localized transfer of heat is represented by arrows extending between heater 26 and temperature-responsive layer portion 32 ). All of temperature-responsive layer 28 that is not heated by heater 26 is unheated portion 34 of temperature-responsive layer 28 .
  • Temperature-responsive layer 28 includes a temperature-responsive material that can exist in two states: a first state that binds molecules or living cells, and a second state that binds substantially less molecules or living cells than the first state (e.g., binds no, or almost no, molecules or living cells).
  • the temperature-responsive material is reversibly convertible to the first state from the second state in response to an effective amount of thermal energy.
  • heating the temperature-responsive material to an appropriate temperature causes it to exist in the first state and to more effectively bind molecules or living cells.
  • binding of molecules or living cells occurs in an aqueous environment.
  • portion 32 of temperature-responsive layer 28 to bind molecules (e.g., proteins, such as antibodies), or living cells, to portion 32 of temperature-responsive layer 28 , portion 32 is heated so that temperature-responsive material exists in the first state, and portion 32 is contacted with an aqueous solution of the molecules, or a preparation of living cells present in an aqueous medium (e.g., cell culture medium).
  • an aqueous medium e.g., cell culture medium.
  • the molecules or cells preferentially bind to heated portion 32 , and bind substantially less efficiently to unheated portion 34 .
  • device 10 may be washed with an aqueous solution to remove unbound cells or molecules.
  • FIG. 4 shows a plan view of a representative device 10 (looking at first surface 14 ) that includes six heaters 26 , identified as first heater 36 , second heater 38 , third heater 40 , fourth heater 42 , fifth heater 44 , and sixth heater 46 , arrayed on first surface 14 .
  • some, or all, of heaters 26 may be controlled independently of other heaters 26 so that some heaters 26 are heating while other heaters 26 are not.
  • these embodiments of device 10 permit some (optionally multiple) portions of temperature-responsive layer 28 to be heated (and so exist in a binding state), while other portions of temperature-responsive layer 28 are not heated (and so exist in a non-binding state). These embodiments of device 10 are useful for simultaneously binding more than one type of molecule and/or living cell to temperature-responsive layer 28 .
  • FIG. 5 shows a plan view (looking at second surface 16 ) of the embodiment of device 10 shown in FIG. 4 , in which a first cell type 48 (represented by squares in FIG. 5 ) is attached to a first temperature-responsive layer portion 50 located on second surface 16 opposite first heater 36 , and to a second temperature-responsive layer portion 52 located on second surface 16 opposite second heater 38 , and to a third temperature-responsive layer portion 54 located on second surface 16 opposite third heater 40 .
  • a second cell type 56 (represented by circles in FIG.
  • the embodiment of device 10 shown in FIGS. 4 and 5 therefore includes six, separate, temperature-responsive layer portions 50 , 52 , 54 , 58 , 60 and 62 , that each have living cells attached to them, while no other portion of temperature-responsive layer 28 has living cells attached to it (or living cells are attached in an amount, and at a density, substantially lower than is found on temperature-responsive layer portions 50 , 52 , 54 , 58 , 60 and 62 ).
  • temperature-responsive layer portion 64 (represented by stippling in FIG. 5 ) encompasses all of temperature-responsive layer 28 except for temperature-responsive layer portions 50 , 52 , 54 , 58 , 60 and 62 , and either has no living cells attached to it, or living cells are attached to temperature-responsive layer portion 64 in an amount, and at a density, substantially lower than is found on temperature-responsive layer portions 50 , 52 , 54 , 58 , 60 and 62 .
  • the embodiment of device 10 shown in FIG. 5 can be made, for example, by activating first heater 36 , second heater 38 , and third heater 40 , so that first temperature-responsive layer portion 50 , second temperature-responsive layer portion 52 , and third temperature-responsive layer portion 54 are heated and exist in a first (binding) state, while the remainder of temperature-responsive layer 28 remains in a second (non-binding) state.
  • Temperature-responsive layer 28 is contacted with an aqueous medium type 48 does not bind to any other portion of temperature-responsive layer 28 except for heated portions 50 , 52 and 54 ; or, if cell type 48 does bind to another portion of temperature-responsive layer 28 , in addition to heated portions 50 , 52 and 54 , binding is substantially less efficient than to heated portions 50 , 52 and 54 .
  • first cell type 48 has bound to heated portions 50 , 52 and 54 of temperature-responsive layer 28
  • aqueous medium that includes first cell type 48 is removed, and fourth heater 42 , fifth heater 44 , and sixth heater 46 are activated, so that fourth temperature-responsive layer portion 58 , fifth temperature-responsive layer portion 60 , and sixth temperature-responsive layer portion 62 are heated and exist in a first (binding) state.
  • Portions 50 , 52 and 54 of temperature-responsive layer 28 also continue to be heated to prevent first cell type 48 from detaching therefrom.
  • Temperature-responsive layer 28 is then contacted with an aqueous medium that includes second cell type 56 which preferentially bind to heated portions 58 , 60 and 62 .
  • Temperature-responsive layer 28 is then washed to remove unbound second cell type 56 .
  • device 10 includes molecules (such as proteins) or one or more living cell(s) bound to one, or more, portions of temperature-responsive layer 28 , but not to the entire surface of temperature-responsive layer 28 .
  • Some embodiments of device 10 include several portions of temperature-responsive layer 28 that each have a single living cell bound thereto. The same type of living cell may be bound to each of the different portions of temperature-responsive layer 28 , or a different type of living cell may be bound to some, or all, of the different portions of temperature-responsive layer 28 .
  • Examples of types of cells that can be attached to one or more portions of temperature responsive layer 28 include granulocytes, chondrocytes, endothelial cells, neural cells, hepatocytes, fibroblasts, epithelial cells, monocytes, polymorphonuclear leukocytes, microglia, cardiac myocytes, keratinocyte, primary bovine aortic smooth muscle cells and human embryonic kidney cells.
  • antibody includes, but is not limited to, polyclonal and monoclonal antibody preparations, CDR-grafted antibody preparations, as well as preparations including hybrid antibodies, altered antibodies, F(AB)′ 2 fragments, F(AB) molecules, Fv fragments, single domain antibodies, chimeric antibodies and functional fragments thereof which exhibit immunological binding properties of the parent antibody molecule.
  • Device body 12 can be made from any electrical or thermal insulator material, such as a plastic or mineral that possesses electrical and thermal insulating properties that prevents most, preferably all, of the heat generated by heater 26 from heating any portion of temperature-responsive layer 28 , except portion 32 on second surface 16 opposite heater 26 .
  • body 12 Representative examples of materials useful for making body 12 include glass, silicon, mica, quartz, sapphire, silicon nitride membrane, silicon dioxide membrane, polytetrafluoroethylene (sold by DuPont under the tradename Teflon®), and poly(ethyleneterephthalate) (sold by DuPont under the tradename Mylar®).
  • Device body 12 can have any desired size and shape. For example, device body 12 can be square, rectangular or circular.
  • the length, width, and height of a rectangular or square device body 12 may each be, for example, from 1 to 10 millimeters, or, for example, from 1 to 10 centimeters.
  • the maximum width of device body 12 (whether device body 12 is a regular or irregular geometric shape) may be, for example, from 1 to 10 millimeters, or, for example, from 1 to 10 centimeters.
  • the height may be, for example, from 1 to 100 micrometers.
  • Body 12 may have a thickness, for example, in the range of from 0.0001 mm to 2 mm.
  • Heaters 26 useful in the practice of the invention produce sufficient heat to cause temperature-responsive layer 28 to change from a first (binding) state to a second (non-binding) state.
  • heaters 26 are disposed on first surface 14 so that there is sufficient distance between adjacent heaters 26 to prevent heat from one heater 26 from spreading to an adjacent heater 26 under normal operating conditions.
  • Embodiments of device 10 that include multiple heaters 26 may include, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 heaters 26 , or may include, for example, between 10 and 50 heaters 26 , or may include, for example, between 10 and 100 heaters 26 .
  • Multiple heaters 26 may be arranged in any pattern, including regular geometric shapes (e.g., rectangular or square arrays), or any irregular pattern.
  • Heater 26 includes heating element 30 , which may be a narrow, thin, film made from metal (see, e.g., K. Henning, et al., In Proc. International Solid State Sensors and Actuators Conference, pp. 825-828 (1997)), or polysilicon (see, e.g., S. W. Janson, Batch-Fabricated Resistojets: Initial Results, In International Electric Propulsion Conference. Cleveland, Ohio, USA IEPC-97-070, (1997)) as a resistor to generate heat over a defined surface area. An electrical current or voltage is applied to heating element 30 to generate heat in accordance with Joule's law.
  • heating element 30 may be a narrow, thin, film made from metal (see, e.g., K. Henning, et al., In Proc. International Solid State Sensors and Actuators Conference, pp. 825-828 (1997)), or polysilicon (see, e.g., S. W. Janson, Batch-Fabricated Resist
  • Heater 26 may be directly deposited onto body 12 which can be, for example, silicon wafer, a glass slide, mica, quartz or plastic. In some cases heater 26 is suspended on a thin membrane (e.g., silicon nitride) in order to minimize conductive heat losses (see, e.g., S. W. Janson, Batch-Fabricated Resistojets: Initial Results, In International Electric Propulsion Conference. Cleveland, Ohio, USA IEPC-97-070, (1997)). Heater 26 may be driven by an electric current via a current source, or electric voltage via a voltage source (see, e.g., Chen, J. K. and Wise, K.
  • a current source e.g., Chen, J. K. and Wise, K.
  • Temperature sensors may be included on body 12 to monitor the temperature, and heater 26 may be used as a temperature sensor (see, e.g., Baroncini, M., et al., Characterization of an embedded micro-heater for gas sensors applications VLSI Technology, Systems, and Applications, 2001. Proceedings of Technical Papers. 2001 International Symposium on 18-20 Apr. 2001 Page(s): 164-167; P. Ruther, et al., Dependence of the Temperature Distribution in Micro Hotplates on Heater Geometry and Heating Mode, Proc. Transducers '03, p. 73-76, (2003)).
  • Heater 26 may be made, for example, by metal deposition and patterning.
  • Metal deposition methods include thermal evaporation deposition, sputtering, thermal spray coating, chemical vapor deposition (CVD), electroplating, or other electroless metal plating.
  • Patterning methods include photolithography, soft lithography, and electron beam lithography.
  • Etching methods include wet etching, plasma etching, ion milling, reactive ion etching, laser etching and liftoff.
  • Other electrically conductive materials, such as poly-silicon can also be used to make heater 26 . Representative methods for making heaters 26 are described, for example, in Gregory T. A.
  • Micro inductor arrays can also be used as heater 26 in the practice of the present invention (see, e.g., Jae Y. Park and Mark G. Allen, “High Current Integrated Microinductors and Microtransformers using Low Temperature Fabrication Processes”, 29th International Symposium on Microelectronics, Minneapolis, Minn., October, 1996 ).
  • Heater 26 can also use chemical reactions to generate heat.
  • Microwell arrays integrated with micro fluid channels can deliver chemicals to a specific site.
  • Micro fluid channels can be fabricated on various substrates, such as silicon, glass, mica, or plastic. Chemical transportation can be achieved, for example, by built-in or external pumps. Fluid channels can dispose of waste and import new chemicals.
  • Temperature-responsive layer 28 is made from any temperature-responsive material, or mixture or blend of temperature-responsive materials, that can exist in a first state that binds molecules or living cells, and that can exist in a second state that binds substantially less molecules or living cells than the first state, and wherein temperature-responsive layer 28 is reversibly convertible to the first state from the second state in response to an effective amount of thermal energy.
  • Temperature-responsive layer 28 may be, for example, only a single layer of molecules of temperature responsive material. Conversion of temperature-responsive layer 28 to the first (binding) state from the second (non-binding) state occurs at a temperature above the lower critical solution temperature (LCST) of the temperature-responsive material used to make temperature-responsive layer 28 .
  • LCST critical solution temperature
  • Conversion of temperature-responsive layer 28 to the second (non-binding) state from the first (binding) state occurs at a temperature below the lower critical solution temperature of the temperature-responsive material used to make temperature-responsive layer 28 .
  • heating temperature-responsive layer 28 above the LCST of the temperature-responsive material from which temperature-responsive layer 28 is made causes temperature-responsive layer 28 to exist in a first (binding) state that preferentially binds molecules and/or living cells.
  • the enhanced ability of the temperature-responsive materials of the present invention to bind cells and/or molecules above their LCST may be due to a change in conformation of the molecules in the temperature-responsive materials that exposes more chemical groups (e.g., NH and C ⁇ O) that can form hydrogen bonds with molecules and/or cells in an aqueous environment.
  • more chemical groups e.g., NH and C ⁇ O
  • poly (N-isopropylacrylamide) (abbreviated as pNIPAM) is useful for making temperature-responsive layer 28 and has an LCST of 31° C.
  • pNIPAM poly (N-isopropylacrylamide)
  • LCST LCST of 31° C.
  • pNIPAM poly (N-isopropylacrylamide)
  • pNIPAM poly (N-isopropylacrylamide)
  • Temperature-responsive layer 28 is typically, although not necessarily, made from a material that possesses a critical solution temperature (LCST) below 37° C. in an aqueous environment.
  • LCST critical solution temperature
  • the following materials are representative examples of materials useful for making temperature-responsive layer 28 (the temperature in parentheses after the name of the material is the LCST for the material, and the citation(s) that follow the name of each material provides a description of that material, or class of materials): homopolymers and copolymers of poly-N-alkyl-substituted acrylamides such as poly(N,N-dimethylacrylamide) (33° C.) (Idziak, I., et al., Macromolecules 32(4):1260-1263, 1999), poly(ethylacrylamide)( 15 ° C.)(Park, S.
  • temperature-responsive layer 28 Other materials useful for making temperature-responsive layer 28 include copolymers and derivatives of methylene oxide (Benkhira, A., et al., Polymer 41(20):7415-7425, 2000), polyethylene oxide and propylene oxide (30-50° C.) (Persson, J., A. Kaul, and F. Tjerneld, Journal of Chromatography B 743(1-2):115-126, 2000), such as copolymers of methoxy poly(ethylene glycol) and poly(propylene fumarate) and vinyl ethers of ethylene glycol (20-90° C.) (Kudaibergenov, S. E., et al., Macromolecular Rapid Communications 16(11):855-860, 1995).
  • Cellulose and derivatives such as hydroxypropylcellulose (Hirsch, S. G. and R. J. Spontak, Polymer 43(1):123-129, 2002), ethyl hydroxyethyl cellulose (Badiger, M. V., A. Lutz, and B. A. Wolf, Polymer 41(4):1377-1384, 2000), and methyl cellulose (29° C.) (Takahashi, M., M. Shimazaki, and J. Yamamoto, Journal of Polymer Science Part B - Polymer Physics 39(1):91-100, 2001) can also be used to make temperature-responsive layer.
  • hydroxypropylcellulose Hirsch, S. G. and R. J. Spontak, Polymer 43(1):123-129, 2002
  • ethyl hydroxyethyl cellulose Badiger, M. V., A. Lutz, and B. A. Wolf, Polymer 41(4):1377-1384, 2000
  • methyl cellulose 29° C.
  • Polyethers such as poly(vinyl methyl ether) (33° C.) (Takada, M., et al., Kobunshi Ronbunshu 51(11):689-693, 1994), butyl vinyl ether (20-90° C.) (Kudaibergenov, S. E., et al., Macromolecular Rapid Communications 16(11):855-860, 1995) and polyglycidol (4-100° C.) (Dworak, A., et al., Polymer Bulletin 50(1-2):47-54, 2003) can also be used to make temperature-responsive layer 28 .
  • temperature-responsive layer 28 Other materials useful for making temperature-responsive layer 28 include polyesters, such as acryloyl-L-proline methyl ester (10-18° C.) (Hiroki, A., et al., Journal of Polymer Science Part A - Polymer Chemistry 36(10):1495-1500, 1998), poly(N-acryloylamino amide)(3-35° C.) derivatives (Dobashi, A., K. Kurata, and M. Senoo, Analytical Sciences 16(8):829-835, 2000), vinyl pyrrolidone and vinyl acetate copolymers (Zhong, Y. Z. and P.
  • polyesters such as acryloyl-L-proline methyl ester (10-18° C.) (Hiroki, A., et al., Journal of Polymer Science Part A - Polymer Chemistry 36(10):1495-1500, 1998), poly(N-acryloylamino amide)(3-35° C.) derivatives (
  • poly(organophosphazenes) (37-75° C.) (Lee, B. H., et al., Macromolecules 35(10):3876-3879, 2002), Poly(2-ethyl-2-oxazoline) (PEtOx) (Christova, D., et al., Polymer 44(8):2255-2261, 2003), Gelatin (Aso, Y., et al., Radiation Physics and Chemistry 55(2):179-183, 1999), poly(N-vinylcaprolactam) (33° C.) (Loos, W., et al., Macromolecular Chemistry and Physics 204(1)1:98-103, 2003), elastin and elastin mimetic polypeptide (33-35° C.) (Wright, E.
  • the present invention provides methods for binding molecules or living cells (or a single living cell) to a temperature-responsive material, wherein the methods each include the step of contacting a temperature-responsive material with a population of molecules or a population of living cells (or a single living cell), wherein: (a) the temperature-responsive material can exist in a first state that binds molecules or living cells, and can exist in a second state that binds substantially less molecules or living cells than the first state, and wherein the temperature-responsive material is reversibly convertible to the first state from the second state in response to an effective amount of thermal energy; and (b) the temperature-responsive material exists in the first state when the temperature-responsive material is contacted with the population of molecules or living cells (or the single living cell), thereby effecting binding of the molecules or living cell(s) to the temperature-responsive material.
  • the temperature-responsive material forms a layer on a surface of a device body.
  • the device body defines a first surface and a second surface that is located opposite the first surface, wherein a heater is disposed upon the first surface, the temperature-responsive material forms a layer on the second surface, and the heater heats the temperature-responsive material so that the temperature-responsive material exists in the first state and binds the molecules or living cells.
  • more than one type of molecule or more than one type of living cell is bound to a temperature-responsive material.
  • These method include the steps of: (a) contacting a temperature-responsive material with a first type of molecules or a first type of living cell(s), wherein the temperature-responsive material is attached to a device body wherein the device body defines a first surface and a second surface that is located opposite the first surface, wherein a first population of heaters and a second population of heaters are disposed upon the first surface, and wherein the temperature-responsive material forms a temperature-responsive layer on the second surface; (b) activating the first population of heaters to heat a first population of temperature-responsive layer portions, located on the second surface opposite the first population of heaters, so that the first type of molecules, or the first type of living cell(s), binds to the first population of temperature-responsive layer portions, said activation occurring before or during the contacting of the temperature-responsive material with the first type of molecules or the first type of living
  • the first population of heaters typically remains activated while the second population of heaters are activated, so that the first type of living cell(s) do not detach from the first population of temperature-responsive layer portions while the second type of living cell(s) is/are being bound to the second population of temperature-responsive layer portions.
  • Temperature-responsive materials useful in construction of device 10 of the present invention are also useful in the practice of the methods for binding molecules or living cells to a temperature-responsive material.
  • Molecules that can be bound to a temperature-responsive material include proteins, such as antibodies. Any type of living cell can be bound to a temperature-responsive material, including the representative cell types disclosed, supra, in connection with device 10 of the invention.
  • Devices 10 of the present invention are useful in the practice of the methods of the present invention for binding molecules or living cells to a temperature-responsive material (e.g., with reference to device 10 shown in FIGS. 1 , 2 and 3 , heater 26 heats portion 32 of temperature-responsive layer 28 so that portion 32 exists in a first (binding) state and binds molecules or living cells). It is not necessary, however, to use devices 10 to practice all embodiments of the methods of the present invention for binding molecules or living cells to a temperature-responsive material.
  • a layer of temperature-responsive material may be formed on a substrate (e.g., a silicon chip), and all, or a portion, of the layer of temperature-responsive material is heated by any useful means, so that the heated material exists in a first (binding) state and binds molecules or living cells.
  • a substrate e.g., a silicon chip
  • all, or a portion, of the layer of temperature-responsive material can be heated by a direct, or indirect, contact with a heater that includes a heating element that produces heat in response to an electrical current, or potential difference, in accordance with Joule's law, or, for example, heat may be applied by an optical device such as a laser beam, or by direct, or indirect, contact with a hot chemical.
  • Devices 10 and methods for binding molecules or living cells to a temperature-responsive material can be used, for example, to study the interactions between living cells, and/or between living cells and their environment.
  • devices 10 of the present invention can be used to study the interaction of first cell type 48 with second cell type 56 in an aqueous environment (e.g., study the physiological response of first cell type 48 to soluble biological molecules released by second cell type 56 ).
  • first cell type 48 may be attached to first portion 50 of temperature-responsive layer 28 of device 10 shown in FIG. 5
  • second cell type 56 may be attached to second portion 52 of temperature-responsive layer 28 of device 10 shown in FIG. 5 .
  • the distance between first portion 50 and second portion 52 is determined by the distance between first heater 36 and second heater 38 .
  • First cell type 48 and second cell type 56 are each completely, or partially, immersed in an aqueous medium.
  • One or more physiological responses of first cell type 48 to soluble biological molecules released by second cell type 56 can be studied (e.g., by measuring the uptake or release of measurably labeled chemicals by first cell type 48 ).
  • different cell types can be attached to different portions of temperature-responsive layer 28 , and each cell type can be exposed to the same environmental stimulus, and the response of each cell type to the stimulus can be determined and compared.
  • devices 10 of the present invention can be used to culture different cell types in physical proximity to each other in vitro.
  • cell interaction between liver cells and fibroblasts has been reported to modulate liver cell growth, migration, and/or differentiation in both the developing and adult liver in vivo.
  • Cocultivation of these two types of cells, in vitro, on devices 10 of the present invention can be used to preserve and modulate hepatocyte phenotype and function for growing bioactive liver tissue in vitro.
  • cell-based drug screening can be performed by attaching one, or more, types of cells to temperature-responsive layer 28 of device 10 of the present invention.
  • the attached cells are then contacted with a candidate drug, and the response to the candidate drug is determined and compared to control cells that were not contacted with the candidate drug (e.g., the control cells may be attached to a different, but otherwise identical, device 10 as the cells that are contacted with the drug).
  • Candidate drugs that elicit a desired response in the cells can be further evaluated for their suitability as drugs for administration to humans or other mammals (see, generally., Bailey, S. N., R. Z. Wu, and D. M. Sabatini, “Applications of transfected cell microarrays in high-throughput drug discovery,” Drug Discovery Today 7(18):S113-S118, 2002).
  • antibody molecules can be attached to temperature-responsive layer 28 .
  • different antibodies can be attached to different portions of temperature-responsive layer 28 on device 10 (e.g., different antibodies can be attached to portions 50 , 52 , 54 , 58 , 60 and 62 of the embodiment of device 10 shown in FIG. 5 ).
  • Device 10 is then contacted with one or more labeled antigens (e.g., fluorescently labeled antigens). Binding of an antigen to a specific antibody can be visualized, for example, with fluorescence microscopy, thereby identifying the binding antigen.
  • labeled antigens e.g., fluorescently labeled antigens
  • one or more candidate antigens can be attached to different portions of temperature-responsive layer 28 (e.g., different antigens can be attached to portions 50 , 52 , 54 , 58 , 60 and 62 of the embodiment of device 10 shown in FIG. 5 ), and then temperature-responsive layer 28 is contacted with one or more labeled antibodies (different antibodies bear a different label if a mixture of antibodies is used). Binding of an antibody to a specific antigen can be visualized, for example, with fluorescence or light microscopy, thereby identifying the antibody that binds to a particular antigen.
  • devices 10 can be used to conduct multiple immunoassays simultaneously.
  • six different, unlabelled, antibodies each having a known specificity for a specific protein or metabolite occurring in human blood, are attached to portions 50 , 52 , 54 , 58 , 60 and 62 of temperature-responsive layer 28 .
  • the first antibody is attached to first portion 50
  • the second antibody is attached to second portion 52
  • the third antibody is attached to third portion 54
  • the fourth antibody is attached to fourth portion 58
  • the fifth antibody is attached to fifth portion 60
  • the sixth antibody is attached to sixth portion 62 .
  • Temperature-responsive layer 28 is contacted with a sample of human blood under conditions that permit the binding of antigens to the antibodies.
  • the blood sample is washed away, and temperature-responsive layer 28 is contacted with a solution containing fluorescently-labeled first, second, third, fourth, fifth and sixth antibodies (that recognize a different portion of the antigen recognized by unlabelled first, second, third, fourth, fifth and sixth antibodies, respectively), wherein the six different antibodies are each labeled with a different fluorescent compound, and the fluorescence produced by each of the six different fluorescent compounds can be distinguished from the fluorescence produced by each of the other five fluorescent compounds.
  • the fluorescence produced by each of the six labeled antibodies is measured and the resulting values used to calculate the amount of each of the six antigens present in the blood sample.
  • the present invention can be used to identify proteases and/or kinases that have substrate specificities that make them attractive candidates as drug targets.
  • one or more candidate proteases and/or kinases are attached to temperature-responsive layer 28 of device 10 .
  • Temperature-responsive layer 28 is then contacted with a fluorogenic or colorimetric substrate.
  • a fluorescent or color signal is produced when the substrate is acted upon (e.g., cleaved or otherwise chemically converted) by a protease and/or kinase, thereby identifying a protease and/or kinase which utilizes the labeled molecule as a substrate.
  • the present invention can be used to characterize the effect(s) on living cells caused by specific proteins (e.g., proteins that are suspected of causing a disease state).
  • proteins e.g., proteins that are suspected of causing a disease state.
  • protein molecules are attached to temperature-responsive layer 28 of device 10 , and living cells are thereafter cultured on temperature-responsive layer 28 . The growth, development, physiology and/or biochemistry of the cultured cells is then analyzed to identify any effect thereon caused by the protein molecules.
  • the present invention provides methods for measuring a response of a population of living cells (or a single living cell) to an agent, wherein each of the methods includes the steps of contacting a population of living cells (or a single living cell) with an agent and measuring a response of the living cell(s) to the agent.
  • the living cell(s) is/are attached to a temperature-responsive material that can exist in a first state that binds living cells, and can exist in a second state that binds substantially less living cells than the first state, wherein the temperature-responsive material is reversibly convertible to the first state from the second state in response to an effective amount of thermal energy.
  • the temperature-responsive material exists in the first state while the living cell(s) is/are contacted with the agent.
  • the agent can be any physical or energetic agent that elicits a response from living cells.
  • the agent can be a chemical molecule (e.g., proteins, nucleic acids), or an energetic stimulus, such as ionizing radiation.
  • the living cells can be any living cells (e.g., mammalian cells, such as the representative mammalian cells disclosed supra). Examples of useful temperature-responsive materials are provided herein in connection with devices 10 of the invention.
  • the living cells are completely, or partially, covered with an aqueous medium (e.g., cell culture medium) which provides moisture and nourishment to the cells.
  • a soluble agent e.g., some candidate drug molecules
  • a response of the living cell(s) to the agent can be measured by any useful means, and the choice of measuring methods and devices depends, to a large extent, on the nature of the response.
  • Representative examples of cell responses that can be measured using the methods of this aspect of the present invention include change in cell morphology, adhesiveness to a substrate, viability, migration, growth, multiplication, ability to uptake or secrete molecules (as a measure of the function of cell membrane channels and transport proteins), protein expression level in the cells, expression of DNA molecules introduced into the cells, and cell electrical impedance signature.
  • the temperature-responsive material forms a layer on a surface of a device body.
  • the device body defines a first surface and a second surface that is located opposite the first surface, wherein a heater is disposed upon the first surface, and the temperature-responsive material forms a layer on the second surface.
  • devices 10 of the present invention can be used in the practice of the methods of the invention for measuring a response of a population of living cells to an agent (e.g., living cells may be bound to temperature-responsive layer portion 32 of device 10 shown in FIGS. 1-3 , and temperature-responsive layer portion 32 may then be contacted with an agent, and the response of the cells to the agent is measured).
  • a multiplicity of different cell types are attached to the temperature-responsive material and are each contacted with the agent, wherein each different cell type is attached to a different portion of the temperature-responsive material.
  • a multiplicity of different cell types can be attached to temperature-responsive layer 28 , and they are each contacted with the agent.
  • Each different cell type is attached to a different portion of temperature-responsive layer 28 .
  • six different cell types can be separately attached to first portion 50 , second portion 52 , third portion 54 , fourth portion 58 , fifth portion 60 and sixth portion 62 of temperature-responsive layer 28 .
  • the present invention provides methods for observing the binding of members of a binding pair, wherein the methods each include the steps of contacting a first member of a binding pair with a second member of a binding pair and observing the binding of the first member of the binding pair with the second member of the binding pair.
  • the first member of the binding pair is attached to a temperature-responsive material that can exist in a first state that binds the first member of the binding pair, and can exist in a second state that binds substantially less of the first member of the binding pair than the first state.
  • the temperature-responsive material is reversibly convertible to the first state from the second state in response to an effective amount of thermal energy, and the temperature-responsive material exists in the first state while the first member of the binding pair is contacted with the second member of the binding pair.
  • binding pairs are molecules and/or living cells.
  • Representative examples of binding pairs include an antibody and the antigen that is recognized and bound by the antibody (the antigen may itself be bound to a cell); an enzyme and its substrate (although it is understood that an enzyme may bind its substrate for a very short period of time); a receptor and its ligand; a cell-adhesive protein and a cell; and complementary nucleic acid molecules.
  • One member of a binding pair is attached to the temperature-responsive material.
  • Either member of a binding pair can be attached to the temperature-responsive material.
  • the binding pair is an antibody and the antigen that is recognized and bound by the antibody, either the antibody or the antigen can be attached to the temperature-responsive material, while the other member of the binding pair is not attached to the temperature-responsive material.
  • binding of the first member of the binding pair with the second member of the binding pair can be observed by any useful means.
  • the binding pair is an antibody and its antigen, and the antibody is attached to the temperature-responsive material
  • the antigen is typically labelled with a chemical moiety that produces a measurable signal so that binding of the antigen by the antibody can be observed.
  • labels include fluorescent materials.
  • binding pair is an enzyme and its substrate, and the enzyme is attached to the temperature-responsive material, binding of the substrate by the enzyme can be observed by means of the formation of a colored product that is produced from the substrate by the enzyme.
  • Amplex Red reagent (from Molecular Probes, PO Box 22010, Eugene, Oreg. 97402-0469) is a fluorogenic substrate for the enzyme horseradish peroxidase. In the presence of horseradish peroxidase, the Amplex Red reagent reacts with a 1:1 stoichiometry with H 2 O 2 to produce highly fluorescent resorufin.
  • the temperature-responsive material forms a layer on a surface of a device body.
  • the device body defines a first surface and a second surface that is located opposite the first surface, wherein a heater is disposed upon the first surface, and the temperature-responsive material forms a layer on the second surface.
  • devices 10 of the present invention can be used in the practice of the methods of the invention for observing the binding of members of a binding pair (e.g., a first member of a binding pair may be bound to temperature-responsive layer portion 32 of device 10 shown in FIGS. 1-3 , and temperature-responsive layer portion 32 may then be contacted with the second member of the binding pair, and the binding of the members of the binding pair is observed).
  • a multiplicity of different first members of a multiplicity of different binding pairs are attached to the temperature-responsive material and are contacted with a multiplicity of different second members of the multiplicity of different binding pairs, wherein each different first member of the multiplicity of different binding pairs is attached to a different portion of the temperature-responsive material.
  • a multiplicity of different first members of a multiplicity of different binding pairs can be attached to temperature-responsive layer 28 , and they are each contacted with a multiplicity of different second members of the multiplicity of different binding pairs. Each different first member of the multiplicity of different binding pairs is attached to a different portion of temperature-responsive layer 28 .
  • first portion 50 can be separately attached to first portion 50 , second portion 52 , third portion 54 , fourth portion 58 , fifth portion 60 and sixth portion 62 of temperature-responsive layer 28 (e.g., a first antibody is attached to first portion 50 , a second antibody is attached to second portion 52 , a third antibody is attached to third portion 54 , a fourth antibody is attached to fourth portion 58 , a fifth antibody is attached to fifth portion 60 , and a sixth antibody is attached to sixth portion 62 ).
  • a first antibody is attached to first portion 50
  • a second antibody is attached to second portion 52
  • a third antibody is attached to third portion 54
  • fourth antibody is attached to fourth portion 58
  • a fifth antibody is attached to fifth portion 60
  • a sixth antibody is attached to sixth portion 62 ).
  • Temperature-responsive layer 28 is then contacted with an aqueous solution including a first antigen recognized by the first antibody, a second antigen recognized by the second antibody, a third antigen recognized by the third antibody, a fourth antigen recognized by the fourth antibody, a fifth antigen recognized by the fifth antibody, and a sixth antigen recognized by the sixth antibody, wherein each of the antigens is labelled with a different fluorescent molecule that produces fluorescence that is distinguishable from the fluorescence produced by the other fluorescent molecules. Binding of the antigens to their respective antibodies is then observed.
  • the methods of this aspect of the invention are useful, for example, for performing immunoassays to observe, and optionally quantify, the binding of antibodies to their corresponding antigens in a fluid or tissue sample removed from a mammalian body (e.g., a human blood sample).
  • the methods of this aspect of the invention are also useful, for example, for identifying novel substrates that are bound by a specific enzyme, or for identifying novel ligands that are bound by a specific receptor molecule.
  • This Example describes a representative method for making device 10 of the present invention.
  • the fabrication method uses a liftoff process for patterning metal films.
  • a thin layer of photosensitive material photoresist
  • a thin metal film was then deposited using a thermal evaporation method.
  • the glass coverslip was then soaked in acetone which dissolves the photoresist.
  • the metal that was deposited directly on the glass coverslip remains, while the metal deposited on the photoresist detaches from the glass coverslip as the photoresist dissolves in the developing solution. This leaves the patterned metal layer that forms the heating elements, on the glass coverslip.
  • an initial cleaning procedure was performed to prepare a substrate for photolithography.
  • the substrate in this case a glass coverslip (VMR, Catalogue No. 48393 252) having dimensions of 24 ⁇ 60 mm, with a thickness of 0.18 mm, was soaked in acetone and ultrasonically agitated for ten minutes in the acetone.
  • the glass coverslip was rinsed with isopropyl alcohol (IPA), and then blow-dried with nitrogen gas. After the initial cleaning procedure, the glass coverslip was heated for one minute on a hot plate at a temperature of 90° C. to drive off the adsorbed water on the surface.
  • IPA isopropyl alcohol
  • the first step of the photolithography process immediately followed the dehydration bake.
  • the glass coverslip was spin coated with a primer (P10) to assist the adhesion of photoresist to the glass.
  • the spin rate was 500 rpm for five seconds, followed by 3000 rpm for thirty seconds.
  • Positive photoresist (AZ1512, available from Clariant Corp.) was then spin coated to the primed glass at 500 rpm for five seconds, followed by 3000 rpm for thirty seconds.
  • the glass coverslip was then prebaked on a hot plate at 90° C. for three minutes to drive off the solvent in the photoresist, and to densify the resist after the spin coating.
  • the glass coverslip was exposed to UV light for six seconds using an Oriel three-inch aligner through a mask, which has the array of designed heating elements.
  • the design included narrow (30 ⁇ m) winding lines that formed the heating elements, and wide long lines with large contacting pads, which formed low resistance electrical contacts.
  • After exposure the glass coverslip was soaked in a developer (MIF 300) for eight seconds. The developer solution only dissolved photoresist in the exposed areas.
  • the glass coverslip was then rinsed with acetone and IPA, and blow dried with nitrogen gas.
  • the glass coverslip was mounted on a silicon wafer (used as a carrier).
  • a clean pipette was used to place a droplet of AZ1512 photoresist (acting as an adhesive) on top of a clean, three-inch silicon wafer.
  • the photoresist was allowed to spread for ten seconds, and then the previously patterned glass coverslip was glued on top of the Az 1512 coated silicon wafer.
  • the glass coverslip and silicon wafer were baked together on a hot plate for ten minutes at 100° C. to dry the photoresist and to ensure a strong bond between the glass coverslip and the carrying silicon wafer.
  • the next step involved metal depositions and was performed in a vacuum CVC thermal evaporation system.
  • a 100 Angstrom (abbreviated as A) thick chromium film was first deposited.
  • One thousand five hundred angstrom thick gold film was then deposited to set the heater resistance to around 100 Ohms.
  • Chromium film was used to enhance adhesion of gold to the glass coverslip.
  • 100 A chromium was again deposited, this time to enhance the gold adhesion to the passivation layer described in the next step.
  • To complete the pattern transfer the glass coverslip and silicon wafer were soaked in acetone for 120 minutes with ultrasonic agitation for 30 seconds.
  • the acetone dissolves the photoresist and thus releases the glass from the three-inch silicon wafer and the metal films which were deposited on the photoresist. Metal films, which were deposited directly on the glass substrate, remain.
  • the substrate is then rinsed with IPA and blow dried with nitrogen gas.
  • the glass substrate with the metallic heaters was coated with silicon nitride thin film that acts as a protection layer from environmental conditions such as high humidity.
  • the contact area was covered with Scotch tape and the substrate was loaded into a Perkin Elmer Randex 2400 sputtering system.
  • the substrate was sputtered with nitride for forty minutes at a background pressure before sputtering of less than 4 micro Torr.
  • the tape was then removed and the glass coverslip was rinsed with acetone and IPA, and blow dried with nitrogen gas.
  • a temperature-responsive ppNIPAM layer was formed by plasma deposition using a plasma reactor connected to a 13.56 MHz radio-frequency power source.
  • 2 g NIPAM monomer (Aldrich) was placed in a 100 mL glass flask.
  • the flask was connected to a metering needle valve for monomer delivery rate control.
  • the monomer flask was heated to 72-75° C. to vaporize NIPAM monomer.
  • the monomer delivery line was maintained at 83° C. during the deposition process.
  • the reactor was pumped to the low 10 ⁇ 3 Torr range.
  • the deposition process included an 80W methane plasma deposition (adhesion promoting layer), followed by NIPAM plasma deposition with stepwise decreasing powers from 80W to 1W with a pressure of 100 mTorr for five minutes and ten minutes, respectively.
  • the ppNIPAM-grafted surfaces were rinsed three times with cold deionized water to remove uncrosslinked molecules before further applications.
  • the high power NIPAM plasma is to form strong crosslink with the substrate to prevent delamination.
  • the low power NIPAM plasma is to preserve the side-chain functionalities that are believed to be the chemical origins of the temperature response.
  • This Example describes preferential binding of various types of animal cells to a temperature-responsive material.
  • NIPAM N-isopropylacrylamid
  • the cell culture supplies were purchased from Gibco Invitrogen Corporation (Carlsbad, Calif.) and filtered though 0.2 ⁇ m filters before use.
  • the cytotoxicity detection kit (Lactate Dehydrogenase (LDH) Assay Kit) was obtained from Roche Diagnostics Corporation (Indianapolis, Ind.).
  • the 1,1′-dioctadecyl-3,3,3′3′-tetramethylindocarbocyanine (Dil)-conjugated acetylated low-density lipoprotein (Dil-Ac-LDL) was purchased from Biomedical Technologies (Stoughton, Mass.) and the FITC mouse monoclonal antibody conjugated to ⁇ -smooth muscle actin from Sigma (St. Louis, Mo.).
  • Polyethylene terephthalate (PET) was purchased from Fisher Scientific Company (Houston, Tex.). Glass coverslips were obtained from VWR scientific (West Chester, Pa.).
  • ppNIPAM temperature-responsive plasma polymerized NIPAM
  • PET poly(ethyleneterephthalate)
  • T tissue culture polystyrene dishes
  • microheater chips a temperature-responsive plasma polymerized NIPAM layer
  • the ppNIPAM-grafted surfaces were rinsed three times with cold deionized water to remove uncrosslinked molecules before use.
  • bovine aortic endothelial cells (BAECs) (a generous gift from Dr. Cecilia Giachelli, University of Washington, Seattle, Wash.) were cultured in DMEM supplemented with 4.5 g/L glucose, 10% fetal bovine serum (FBS), 0.1 mM MEM non-essential amino acids, 1 mM MEM sodium pyruvate, 100 U/mL penicillin and 100 mg/mL streptomycin.
  • Primary bovine aortic smooth muscle cells BASMCs (a generous gift from Dr.
  • Cecilia Giachelli University of Washington, Seattle, Wash.
  • DMEM fetal bovine serum
  • 1 mM sodium pyruvate 100 U/mL penicillin and 100 mg/mL streptomycin.
  • HEK-293 cells were maintained in DMEM supplemented with 4.5 g/L glucose, 10% FBS, 100 U/mL penicillin and 100 mg/mL streptomycin.
  • BAECs and HEK-293 cells were between passages 3 and 10.
  • BAECs used in the study were between passage 7 and 15.
  • Cell incubation was performed at 37° C. in a humidified atmosphere with 5% CO 2 . The cells were dissociated from the culture flasks with trypsin/EDTA, washed with DPBS and resuspended in the respective culture media prior to the adhesion or patterning experiments.
  • ppNIPAM plasma polymerized NIPAM
  • TCPS tissue culture polystyrene
  • the cell morphology was observed under a phase contrast microscope (Nikon TE200 Inverted Microscope).
  • the number of attached cells was determined using LDH assay, which is based on the principle of releasing the cytoplasmic enzyme LDH and measuring its activity in the supernatant. Briefly, the samples with adhered cells were washed twice with DPBS and cells were permeablized with 500 ⁇ l 1% triton-X100 for 30 minutes. 100 ⁇ l of the supernatant was transferred to a 96 well TCPS plate and mixed with the reaction solution for 30 minutes at room temperature. The absorbance of the solution was measured at 490 nm using a SpectraCountTM plate reader (Packard) and fitted onto a standard curve to determine the number of cells on each surface. The number of attached cells at each test condition was plotted with 6 replicas.
  • ppNIPAM was directly coated on a 48 well TCPS plate. 1 ml cells were seeded at a cell density of 5 ⁇ 10 4 cells/ml in complete media. Cells cultured on untreated TCPS served as a control. The cells were cultured at 37° C. in a humidified atmosphere with 5% CO 2 and observed every day under a phase contrast microscope (Nikon TE200 Inverted Microscope). To test the response of the confluent cell sheet to temperature drop, the wells with confluent cell sheets were rinsed twice with DPBS and replenished with serum-free DMEM at room temperature. The plates were left at room temperature for 2 hours and observed.
  • a ppNIPAM-coated microheater chip was prepared as described in Example 1.
  • a Teflon® chamber was built to hold the reaction solution only in contact with the side opposite to the metallic heating wires so that the heating wires were isolated from the electrolyte.
  • a layer of thermochromic liquid crystal paint was applied on top of ppNIPAM on a test chip.
  • Cell patterning was performed using BAEC and BASMC from serum-free media. 400 ⁇ l BASMC suspended in serum-free DMEM was added to the chamber at a density of 2 ⁇ 10 5 /ml to promote confluent cell adhesion. One heater was turned on with determined power input for 3 hours. The chip was rinsed three times with DPBS and 400 ⁇ l BAEC suspended in serum-free DEME was seeded at the same density with a second heater on for another three hours. The first heater was kept “on” during the whole process to prevent cell detachment.
  • the cell-patterned chip was incubated with DMEM supplemented with 10% FBS and 4 ⁇ g/ml Dil-Ac-LDL at 37° C. for 4 hours to label BAECs.
  • BAECs specifically take up the Dil-Ac-LDL and store it in the endosomal granula.
  • the chip was washed with DPBS and the cells were fixed with 4% paraformaldehyde/0.1% Triton X-100 for 10 minutes.
  • the chip was blocked with 1% BSA in DPBS for 30 minutes and reacted with an FITC-labeled-rabbit-polyclonal anti-bovine smooth muscle actin antibody at 1:100 dilution for 30 minutes at room temperature.
  • the chip was observed under a fluorescence microscope (Nikon TE200 Inverted Microscope). The double stained images were superimposed with software (Metamorph Image).
  • Cell Adhesion Cell adhesion on ppNIPAM coated PET, bare PET and TCPS were tested at either room temperature (below LCST) or 37° (above LCST). At 37° C., BAECs and BASMCs behaved similarly on the thermoresponsive and control surfaces after 3 hours incubation. Large number of cells were found to attach, adhere and spread on ppNIPAM, PET and TCPS from either serum-free or low serum-containing media (1% FBS for BAECs and 1.5% for BASMCs). However at room temperature, the effect of the ppNIPAM layer on cell behavior was immediately apparent.
  • BAECs, BASMCs and HEK-293 cells proliferated very similarly on TCPS, PET and ppNIPAM coated TCPS from complete media at 37° C. All three cell types reached confluence after 72 hours incubation on the three surfaces. The morphology of the cells was identical on ppNIPAM and control surfaces at confluence. When confluent HEK-293 and BAEC cells were transferred to room temperature, cell sheets were observed to come off immediately from ppNIPAM coated TCPS, but not from TCPS or bare PET, even after 12 hours at room temperature.
  • a microheater array chip was made that included a temperature-responsive ppNIPAM layer heated by three separate microheaters to spatially control the phase transition and cell adhesion on the ppNIPAM surface.
  • the microheater array used in this work had three independent heaters. The resistance of each heating element was measured to be around 100 ⁇ .
  • the chip was connected to a power source and contacted solution only on the side opposite to the metal layers. By monitoring with a layer of thermochromic liquid crystal paint, it was observed that 50 mW input power was required to heat the ppNIPAM surface to 35° C. -40° C. with 400 ⁇ l buffer in the chamber.
  • the cell patterning was first tested with a single type of cells. After seeding BAECs on ppNIPAM-coated microheater array chip for 3 hours with two heaters ‘on’, the cells were stained with Dil-Ac-LDL and observed under a fluorescence microscope. Ac-LDL is specifically uptaken by viable endothelial cells, so it gives information about both the viability and localization of the BAECs. Localized cell adhesion was observed, which associated with the heaters that were turned on. The pattern shape resembled the heating area observed using the thermochromic liquid crystal paint. These indicated that localized cell adhesion was driven by a temperature-induced polymer property change.
  • BAECs and BASMCs were sequentially added into the Teflon® chamber with two different heaters being turned on in sequence. To prevent detachment of the first type of adhered cells, the first heater was left on during the whole process. BAECs and BASMCs were stained afterwards with molecules specific to cell types. Localized adhesion of the two types of cells was observed after staining. When a control experiment was performed with a microheater chip lacking the ppNIPAM coating, non-specific adhesion was observed all over the chip regardless of the heated or cold area.
  • This Example describes preferential binding of various types of proteins to an area of pNIPAM heated by a microheater.
  • ppNIPAM grafted surfaces were prepared by exposing 0.8 mm-by-0.8 mm PET or microheater chips to NIPAM glow discharge under continuous plasma, as described in Example 1. The ppNIPAM-grafted surfaces were rinsed three times with cold deionized water to remove uncrosslinked monomers before use.
  • Radiolabeled proteins were added to unlabeled protein solutions to obtain a specific activity of 5 cpm/ng and final protein concentration of 0.03, 0.1 and 0.05 mg/ml for fibrinogen, BSA and IgG adsorption, respectively. Amounts of adsorbed proteins were calculated from the retained radioactivity (corrected for background) and the specific activity of the protein solution.
  • a ppNIPAM coated microheater chip was prepared as described in Example 1.
  • the size of the heating elements used in this study was 1 mm by 1 mm.
  • the resistance of the heating elements was around 100 ⁇
  • ppNIPAM was deposited as the functional layer on the side opposite to the heaters.
  • a Teflon® chamber was built to hold the solutions in contact with only the ppNIPAM-coated side.
  • a layer of thermochromic liquid crystal paint was applied on top of the heaters to monitor the surface temperature at different heating powers.
  • Protein patterning was performed by first adding 400 ⁇ l 0.05 mg/ml FITC-anti-BSA into the chamber, turning on one heater with 50 mW power supply and allowing protein to adsorb for 0.5 hours. The chip was rinsed 3 times with CPBS, followed by TRITC-goat-IgG adsorption in the same manner.
  • Protein Patterning Results Protein patterning on the ppNIPAM coated microheater array was performed using FITC-labeled goat IgG and TRITC-labeled anti-BSA. The two proteins were added in the chamber sequentially with two different heaters turned on at 50 mW. Each protein was allowed to adsorb for 30 minutes. Preferential adsorption of each protein was expected to localize directly on top of the corresponding working heater. Site-specific adsorption of the two proteins was observed under a fluorescent microscope.
  • This Example describes the use of the present invention to discover drug candidates for treatment of diabetes based upon the known effect of the glucagon-like peptide 1 (GLP-1) to increase insulin secretion in pancreatic beta-islet cells (see, Miguel, J. C. et al. Biochemical Pharmacology 65:283-292, 2003).
  • GLP-1 glucagon-like peptide 1
  • a sample reservoir contains rat BRIN BD11 cells, cultured in RPMI 1640 media containing 10% fetal calf serum, 100 U/ML penicillin, 0.1 mg/mL streptomycin and 11.1 mM glucose. All these media components are purchased from GIBCO Life Technologies.
  • a micro-fluidic stream of cells from the sample reservoir is loaded into an array chamber, followed by raising the temperature to 37° C. only in the array zones where it is desired for cells to attach. Following adsorption of the cells, unbound cells are washed off the rest of the array with cell-free RPMI media.
  • a second set of different cells, such as the human pancreatic beta-islet cell line MIN6 are thermally localized to different zones in the array. Each of these cell types includes the GLP-1 receptor.
  • the mixed cell array is treated in sequential fashion with candidate agonists, or antagonists, of the GLP-1 receptor.
  • the candidate molecules hereafter referred to as drugs
  • the drugs are contained in separate sample reservoirs in the microfluidic stream.
  • the drugs can be dissolved in either serum-free RPMI medium or, in order to assess the bioavailability of the drugs to the cells due to serum protein binding, RMPI supplemented with 10% fetal bovine serum.
  • the cells are cultured at 37° C., followed by analysis of insulin expression either by staining the entire array with anti-insulin antibodies to detect a decrease in insulin secretion, or by hybridization of the entire array with DNA probes for insulin RNA expression.
  • the effect of the drug on the different cell types provides critical information pertaining to the specificity of the drug.
  • This specificity can be ascertained further by inclusion of non-GLP responsive insulin secreting cells, which can be created by silencing the GLP-1 receptor in the cell lines through genetic engineering, or pre-incubation with GLP-1 receptor antibodies.
  • non-GLP responsive insulin secreting cells which can be created by silencing the GLP-1 receptor in the cell lines through genetic engineering, or pre-incubation with GLP-1 receptor antibodies.
  • micro-heater arrays e.g., 50 square microns
  • cellular drug-sensitivity assays are confounded by having, in a population of clonally selected identical cells, varying sensitivity to the drug. This variance makes it difficult to compare precisely the potency and metabolism of a given compound. Separating the population into single cells, affords a significant enhancement to the power of the analysis.
  • the system enables the precise detection of more potent and selective synthetic low-molecular weight synthetic drugs agonists of GLP-1 that promote insulin secretion in diabetics.
  • This Example describes the use of the present invention to discover, or optimize, drug candidates that specifically inhibit the interaction of FOXO1 and PPARGC1 transcription factors that are believed to be involved in the development of type II diabetes.
  • an array is created by applying a stream of solution of Dulbecco's phosphate buffered saline (DPBS) containing either FOXO1 or PPARGC1, in a pattern produced via control of the temperature in each zone of the array.
  • DPBS Dulbecco's phosphate buffered saline
  • the other partner of the protein pair is introduced in the presence or absence of the drug candidate. If the drug is capable of inhibiting the binding of FOXO1 to PPARGC1, then the second protein (FOXO1 or PPARGC1) will not bind to the thermally-pre-adsorbed partner.
  • Control zones in the array are created to be devoid of protein, or to contain a different protein that does not bind FOXO1 or PPARGC1. In this way the specificity and integrity of protein-pair binding is determined.
  • thermally-controlled array is especially useful to assemble these complexes under precise control one protein at a time.
  • drug candidates can be screened that inhibit the precise three-dimensional structure that is only present at the time of assembly.
  • Such studies of protein dynamics are difficult to perform in solution. They are made possible by the ability of the thermally-controlled array system to isolate temporally and spatially the assembly of multi-component protein complexes.

Landscapes

  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Immunology (AREA)
  • Wood Science & Technology (AREA)
  • Organic Chemistry (AREA)
  • Bioinformatics & Cheminformatics (AREA)
  • Zoology (AREA)
  • Biomedical Technology (AREA)
  • General Health & Medical Sciences (AREA)
  • Microbiology (AREA)
  • Biotechnology (AREA)
  • Biochemistry (AREA)
  • General Engineering & Computer Science (AREA)
  • Genetics & Genomics (AREA)
  • Sustainable Development (AREA)
  • Molecular Biology (AREA)
  • Urology & Nephrology (AREA)
  • Hematology (AREA)
  • Cell Biology (AREA)
  • Clinical Laboratory Science (AREA)
  • Food Science & Technology (AREA)
  • Medicinal Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Analytical Chemistry (AREA)
  • General Physics & Mathematics (AREA)
  • Pathology (AREA)
  • Apparatus Associated With Microorganisms And Enzymes (AREA)
  • Micro-Organisms Or Cultivation Processes Thereof (AREA)
US10/630,235 2002-07-30 2003-07-29 Apparatus and methods for binding molecules and cells Expired - Fee Related US7442515B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US10/630,235 US7442515B2 (en) 2002-07-30 2003-07-29 Apparatus and methods for binding molecules and cells

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US39979302P 2002-07-30 2002-07-30
US10/630,235 US7442515B2 (en) 2002-07-30 2003-07-29 Apparatus and methods for binding molecules and cells

Publications (2)

Publication Number Publication Date
US20040053334A1 US20040053334A1 (en) 2004-03-18
US7442515B2 true US7442515B2 (en) 2008-10-28

Family

ID=31188619

Family Applications (1)

Application Number Title Priority Date Filing Date
US10/630,235 Expired - Fee Related US7442515B2 (en) 2002-07-30 2003-07-29 Apparatus and methods for binding molecules and cells

Country Status (3)

Country Link
US (1) US7442515B2 (fr)
AU (1) AU2003259289A1 (fr)
WO (1) WO2004011669A2 (fr)

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080160559A1 (en) * 2006-06-12 2008-07-03 Carre Alain R E Thermo-responsive blends and uses thereof
US8163886B2 (en) 2006-12-21 2012-04-24 Emd Millipore Corporation Purification of proteins
US8362217B2 (en) 2006-12-21 2013-01-29 Emd Millipore Corporation Purification of proteins
US20130240444A1 (en) * 2012-03-19 2013-09-19 Samsung Electronics Co., Ltd. Thermosensitive copolymers, forward osmosis water treatment devices including the same, and methods of producing and using the same
US8569464B2 (en) 2006-12-21 2013-10-29 Emd Millipore Corporation Purification of proteins
US8691918B2 (en) 2010-05-17 2014-04-08 Emd Millipore Corporation Stimulus responsive polymers for the purification of biomolecules
US8999702B2 (en) 2008-06-11 2015-04-07 Emd Millipore Corporation Stirred tank bioreactor
US9090930B2 (en) 2006-06-27 2015-07-28 Emd Millipore Corporation Method and unit for preparing a sample for the microbiological analysis of a liquid
US9541480B2 (en) 2011-06-29 2017-01-10 Academia Sinica Capture, purification, and release of biological substances using a surface coating
US9803165B2 (en) 2008-12-16 2017-10-31 Emd Millipore Corporation Stirred tank reactor and method
US10107726B2 (en) 2016-03-16 2018-10-23 Cellmax, Ltd. Collection of suspended cells using a transferable membrane
US10112198B2 (en) 2014-08-26 2018-10-30 Academia Sinica Collector architecture layout design
US10167546B2 (en) * 2015-04-29 2019-01-01 3M Innovative Properties Company Swellable film forming compositions and methods of nanoimprint lithography employing same
US10495644B2 (en) 2014-04-01 2019-12-03 Academia Sinica Methods and systems for cancer diagnosis and prognosis

Families Citing this family (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060091015A1 (en) * 2004-11-01 2006-05-04 Applera Corporation Surface modification for non-specific adsorption of biological material
DE102004061731B4 (de) * 2004-12-17 2006-12-14 Technische Universität Dresden Programmierbarer Mikrostempel
WO2006114098A2 (fr) * 2005-04-26 2006-11-02 Aarhus Universitet Materiau biocompatible pour implants chirurgicaux et surfaces de culture cellulaire de guidage de cellules
US20070095666A1 (en) * 2005-10-27 2007-05-03 Applera Corporation Surface Modification in a Manipulation Chamber
US20080153077A1 (en) * 2006-06-12 2008-06-26 David Henry Substrates for immobilizing cells and tissues and methods of use thereof
US8080593B2 (en) * 2006-11-29 2011-12-20 University Of Southern California Reversible thermoresponsive adhesives for implants
JP2008228585A (ja) * 2007-03-16 2008-10-02 Canon Inc 細胞培養容器および細胞培養装置
US20080227664A1 (en) * 2007-03-16 2008-09-18 Canon Kabushiki Kaisha Cell array structural body and cell array
US8329117B2 (en) 2009-05-14 2012-12-11 Canon U.S. Life Sciences, Inc. Microfluidic chip features for optical and thermal isolation
GB0908372D0 (en) * 2009-05-15 2009-06-24 Univ Manchester Temperature-responsive co-polymers and uses thereof
DE102010012252A1 (de) * 2010-03-22 2011-09-22 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Thermoresponsives Substrat mit Mikrogelen, Verfahren zu dessen Herstellung und Kultivierungsverfahren für biologische Zellen
DE102010012254A1 (de) * 2010-03-22 2011-09-22 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Substrat, Kultivierungseinrichtung und Kultivierungsverfahren für biologische Zellen
WO2013173463A1 (fr) * 2012-05-15 2013-11-21 Cornell University Triple immunocoloration d'erg/tff3/hmwck pour la détection du cancer de la prostate
JP6638930B2 (ja) * 2015-05-08 2020-02-05 国立大学法人福井大学 アルケニルエーテル−ビニルエステル共重合体
FR3130032B1 (fr) * 2021-12-03 2025-04-11 Commissariat Energie Atomique Système automatisé de préparation d'un échantillon biologique

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5776748A (en) 1993-10-04 1998-07-07 President And Fellows Of Harvard College Method of formation of microstamped patterns on plates for adhesion of cells and other biological materials, devices and uses therefor
US5858687A (en) * 1993-04-12 1999-01-12 The United States Of America As Represented By The Department Of Health And Human Services Cell bioassay of neurotoxins
US6471761B2 (en) 2000-04-21 2002-10-29 University Of New Mexico Prototyping of patterned functional nanostructures
US6491061B1 (en) 2000-02-25 2002-12-10 University Of New Mexico Stimuli responsive hybrid materials containing molecular actuators and their applications
US6939515B2 (en) * 2001-08-10 2005-09-06 Symyx Technologies, Inc. Apparatuses and methods for creating and testing pre-formulations and systems for same
US7020355B2 (en) * 2001-11-02 2006-03-28 Massachusetts Institute Of Technology Switchable surfaces

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6168948B1 (en) * 1995-06-29 2001-01-02 Affymetrix, Inc. Miniaturized genetic analysis systems and methods
WO1998053311A2 (fr) * 1997-05-23 1998-11-26 Gamera Bioscience Corporation Dispositifs et procedes permettant d'utiliser l'acceleration centripete pour commander le deplacement de fluides sur un systeme microfluidique
US6174675B1 (en) * 1997-11-25 2001-01-16 Caliper Technologies Corp. Electrical current for controlling fluid parameters in microchannels

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5858687A (en) * 1993-04-12 1999-01-12 The United States Of America As Represented By The Department Of Health And Human Services Cell bioassay of neurotoxins
US5776748A (en) 1993-10-04 1998-07-07 President And Fellows Of Harvard College Method of formation of microstamped patterns on plates for adhesion of cells and other biological materials, devices and uses therefor
US5976826A (en) 1993-10-04 1999-11-02 President And Fellows Of Harvard College Device containing cytophilic islands that adhere cells separated by cytophobic regions
US6368838B1 (en) 1993-10-04 2002-04-09 President And Fellows Of Havard College Adhering cells to cytophilic islands separated by cytophobic regions to form patterns and manipulate cells
US6491061B1 (en) 2000-02-25 2002-12-10 University Of New Mexico Stimuli responsive hybrid materials containing molecular actuators and their applications
US6471761B2 (en) 2000-04-21 2002-10-29 University Of New Mexico Prototyping of patterned functional nanostructures
US6939515B2 (en) * 2001-08-10 2005-09-06 Symyx Technologies, Inc. Apparatuses and methods for creating and testing pre-formulations and systems for same
US7020355B2 (en) * 2001-11-02 2006-03-28 Massachusetts Institute Of Technology Switchable surfaces

Non-Patent Citations (90)

* Cited by examiner, † Cited by third party
Title
Achiha, K., et al., "Interactions Between Temperature-Sensitive Hydrogel Microspheres and Granulocytes," Polymers for Advanced Technologies 6(7):534-540, 1995.
An, Y.H., et al., "Regaining Chondrocyte Phenotype in Thermosensitive Gel Culture," Anatomical Record 263(4):336-341, 2001.
Aoki, T., et al., "Effect of Phenylboronic Acid Groups in Copolymers on Endothelial Cell Differentiation Into Capillary Structures," Journal of Biomaterials Science-Polymer Edition 9(1):1-14, 1997.
Arenkov, P., et al., "Protein Microchips: Use for Immunoassay and Enzymatic Reactions," Analytical Biochemistry 278(2):123-131, 2000.
Aso, Y., et al., "Thermally Controlled Protein Release From Gelatin-Dextran Hydrogels," Radiation Physics and Chemistry 55(2):179-183, 1999.
Badiger, M.V., et al., "Interrelation Between the Thermodynamic and Viscometric Behaviour of Aqueous Solutions of Hydrophobically Modified Ethyl Hydroxyethyl Cellulose," Polymer 41(4):1377-1384, 2000.
Baier, R.E., et al., "Surface Properties Determine Bioadhesive Outcomes: Methods and Results," J. Biomed. Mater. Res. 18(4):337-355, 1984.
Bailey, S.N., et al., "Applications of Transfected Cell Microarrays in High-Throughput Drug Discovery," Drug Discovery Today 7(18):S113-S118, 2002.
Benesch, J., et al., "Protein Adsorption to Oligo(Ethylene Glycol) Self-Assembled Monolayers: Experiments with Fibrinogen, Heparinized Plasma, and Serum," J. Biomater. Sci.-Polym. Ed. 12:581-597, 2001.
Benkhira, A., et al., "Interactions of Ethylene Oxide/Methylene Oxide Copolymers With Sodium Dodecyl Sulphate," Polymer 41(20):7415-7425, 2000.
Bhatia, S.N., et al., "Effect of Cell-Cell Interactions in Preservation of Cellular Phenotype: Cocultivation of Hepatocytes and Nonparenchymal Cells," FASEB J. 13(14):1883-1900, Nov. 1999.
Biran, I., and D.R. Walt, "Optical Imaging Fiber-Based Single Live Cell Arrays: A High-Density Cell Assay Platform," Anal. Chem. 74(13):3046-3054, Jul. 1, 2002.
Bohanon, T., et al., "Neural Cell Pattern Formation on Glass and Oxidized Silicon Surfaces Modified With Poly(N-Isopropylacrylamide)," J. of Biomater. Sci. Polymer Edn. 8(1):19-39, 1996.
Bohdanecký, M., et al., "Cloud Point Curves of Aqueous Solutions of Poly(N-Ethylmethacrylamide)," Collection of Czechoslovak Chemical Communications 58(10):2370-2382, Oct. 1993.
Böhringer, K.F., "Surface Modification and Modulation in Microstructures: Controlling Protein Adsorption, Monolayer Desorption and Micro-Self-Assembly," J. Micromech. Microeng. 13:S1-S10, 2003.
Chen, G., et al., "Effect of Protein and Cell Behavior on Pattern-Grafted Thermoresponsive Polymer," J. Biomed. Mater. Res. 42:38-44, 1998.
Chevillard, C., and M.A.V. Axelos, "Phase Separation of Aqueous Solution of Methylcellulose," Colloid Polym. Sci. 275(6):537-545, Jun. 1997.
Chiu, D.T., et al., "Patterned Deposition of Cells and Proteins Onto Surfaces by Using Three-Dimensional Microfluidic Systems," Proc. Natl. Acad. Sci. USA 97(6):2408-2413, Mar. 14, 2000.
Christova, D., et al., "New Thermo-Responsive Polymer Materials Based on Poly(2-Ethyl-2-Oxazoline) Segments," Polymer 44(8):2255-2261, 2003.
Curti, P.S., et al., "Surface Modification of Polystyrene and Poly(ethylene terephtalate) by Grafting Poly(N-Isopropylacrylamide)," J. Mater. Sci.-Mater. Med. 13(12):1175-1180, Dec. 2002.
d'Agostino, R., et al., (eds), Plasma Processing of Polymers, NATO-ASI Series E: Applied Sciences vol. 346, Kluwer Academic Publishers, Dordrecht, The Netherlands, 1996, pp. 347-363.
Dobashi, A., et al., "Control of the Solubility Transition in Novel Temperature-Responsive Linear Polymers Comprising alpha-Amino Acid Diamide Derivatives," Analytical Sciences 16(8):829-835, Aug. 2000.
Dorn, I.T., et al., "Diacetylene Chelator Lipids as Support for Immobilization and Imaging of Proteins by Atomic Force Microscopy," Langmuir 14(17):4386-4842, 1998.
Dworak, A., et al., "Hydrophobically Modified Polyglycidol-the Control of Lower Critical Solution Temperature," Polymer Bulletin 50(1-2):47-54, 2003.
Elwing, H., et al., "A Wettability Gradient Method for Studies of Macromolecular Interactions at the Liquid/Solid Interface," J. Colloid Interface Sci. 119(1):203-210, Sep. 1987.
Figeys, D., "Array and Lab on a Chip Technology for Protein Characterization," Curr. Opin. Mol. Ther. 1(16):685-694, 1999.
Folch, A., et al., "Microfabricated Elastomeric Stencils for Micropatterning Cell Cultures," J. Biomed. Mater. Res. 52:346-353, 2000.
Folch, A., et al., "Molding of Deep Polydimethylsiloxane Microstructures for Microfluidics and Biological Applications," J. Biomech. Eng.-Trans. ASME 121:28-34, Feb. 1999.
Gan, L.H., et al., "New Stimuli-Responsive Copolymers of N-Acryloyl-N '-Alkyl Piperazine and Methyl Methacrylate and Their Hydrogels," Polymer 42(1):65-69, 2001.
Groves, J.T., "Membrane Array Technology for Drug Discovery," Current Opinion in Drug Discovery & Development 5(4):606-612, 2002.
Hanein, Y., et al., "Micromachining of Non-Fouling Coatings for Bio-MEMS Applications," Sensors and Actuators B 81:49-54, 2001.
Hiroki, A., et al., "P-Nitrophenol Permeability and Temperature Characteristics of an Acryloyl-L-Proline Methyl Ester-Based Porous Gel Membrane," J. of Polymer Sci. Part A: Polymer Chem. 36(10):1495-1500, 1998.
Hirose, M., et al., "Temperature-Responsive Surface for Novel Co-Culture Systems of Hepatocytes With Endothelial Cells: 2-D Patterned and Double Layered Co-Cultures," Yonsei Medical J. 41(6):803-813, 2000.
Hirsch, S.G., and R.J. Spontak, "Temperature-Dependent Property Development in Hydrogels Derived From Hydroxypropylcellulose," Polymer 43(1):123-129, 2002.
Hong, J.S., et al., "Cloud Points and Phase Separation of Aqueous Poly(N-Vinylacetamide) Solutions in the Presence of Salts," Colloid and Polym. Sci. 274(11):1013-1019, Nov. 1996.
Horbett, T.A., et al., "Cell Adhesion to a Series of Hydrophilic-Hydrophobic Copolymers Studies With a Spinning Disk Apparatus," J. Biomed. Mater. Res. 22(5):383-404, May 1988.
Hourdet, D., et al., "Reversible Thermothickening of Aqueous Polymer Solutions," Polymer 35(12):2624-2630, 1994.
Idziak, I., et al., "Thermosensitivity of Aqueous Solutions of Poly(N,N-Diethylacrylamide)," Macromolecules 32(4):1260-1263, 1999.
Ito, Y., et al., "Patterned Immobilization of Thermoresponsive Polymer," Langmuir 13(10):2756-2759, 1997.
Kane, R.S., et al., "Patterning Proteins and Cells Using Soft Lithography," Biomaterials 20:2363-2376, 1999.
Katono, H., et al., "Thermoresponsive Swelling and Drug Release Switching of Interpenetrating Polymer Networks Composed of Poly (Acrylamide- Co-Butyl Methacrylate) and Poly (Acrylic-Acid)," Journal of Controlled Release 16(1-2):215-227, 1991. <http://www.sciencedirect.com/science?<SUB>-</SUB>ob=ArticleURL&<SUB>-</SUB>udi=B6T3D-475TCXK-12J&<SUB>-</SUB>user=10&<SUB>-</SUB>handle=...> [Abstract retrieved Jan. 9, 2004].
Kim, Y.D., et al., "Stable Sol-Gel Microstructured and Microfluidic Network for Patterning," Biotechnol. Bioeng. 73(5):331-337, Jun. 5, 2001.
Klages, C.-P., "Modification and Coating of Biomaterial Surfaces by Glow-Discharge Processes. A Review," Mat.-wiss. u. Werkstofftech 30:767-774, 1999.
Kubota, N., et al., "Temperature-Responsive Properties of Poly(acrylic acid-co-acrylamide)-graft-Oligo(ethylene glycol) Hydrogels," J. of Appl. Polym. Sci. 80:798-805, 2001.
Kudaibergenov, S.E., et al., "Temperature-Responsive Swelling and Deswelling of the Copolymers from Vinyl Ether of Ethylene Glycol and Butyl Vinyl Ether," Macromol. Rapid Commun. 16(11):855-860, Nov. 1995.
Kunugi, S., et al., "Microcalorimetric Study of Aqueous Solution of a Thermoresponsive Polymer Poly(N-Vinylisobutyramide) (PNVIBA)," Polymer Journal 34(5):383-388, May 2002.
Kushida, A., et al., "Two-Dimensional Manipulation of Differentiated Madin-Darby Canine Kidney (MDCK) Cell Sheets: The Noninvasive Harvest from Temperature-Responsive Culture Dishes and Transfer to Other Surfaces," J. Biomed. Mater. Res. 54(1):37-46, 2001.
Lee, B.H., et al., "A Thermosensitive Poly(Organophosphazene) Gel," Macromolecules 35(10):3876-3879, 2002.
Lee, R.J., and L. Huang, "Lipidic Vector Systems for Gene Transfer," Critical Reviews in Therapeutic Drug Carrier Systems 14(2):173-206, 1997.
Lee, W.-F., and G.-C. Hung, "Thermoreversible Hydrogels .I. Synthesis and Effect of a Hydrophobic Monomer on Swelling Behaviors of Thermoreversible Gels Prepared by Copolymerizing N-Alkoxyalkylacrylamide with Butyl Acrylate," J. Appl. Polym. Sci. 64(8):1477-1484, May 23, 1997.
Lin, S.-Y., et al., "Thermal Micro ATR/FT-IR Spectroscopic System for Quantitative Study of the Molecular Structure of Poly(N-Isopropylacrylamide) in Water," Polymer 40:2619-2624, 1999.
Loos, W., et al., "Thermo-Responsive Organic/Inorganic Hybrid Hydrogels Based on Poly(N-Vinylcaprolactam)," Macromol. Chem. Phys. 204(1):98-103, 2003.
Lydon, M.J., et al., "Cellular Interactions With Synthetic Polymer Surfaces in Culture," Biomaterials 6(6):396-402, Nov. 1985.
MacBeath, G., and S.L. Schreiber, "Printing Proteins as Microarrays for High-Throughput Function Determination," Science 289(5485):1760-1763, Sep. 8, 2000.
Maeda, Y., et al., "Hydration and Phase Behavior of Poly(N-Vinylcaprolactam) and Poly(N-Vinylpyrrolidone) in Water," Macromolecules 35(1):217-222, 2002.
Marczak, W., and A. Banas, "The Hydrophobic and Hydrophilic Interactions in the System 2,4,6-Trimethylpyridine-Water in the Vicinity of and Above the Lower Critical Solution Temperature," Fluid Phase Equilibria 186(1-2):151-164, 2001.
Merrett, K., et al., "Adhesion of Corneal Epithelial Cells to Cell Adhesion Peptide Modified pHEMA Surfaces," J. Biomater. Sci. Polymer Edn. 12(6):647-671, 2001.
Moselhy, J., et al., "In Vitro Studies of the Interaction of Poly(NIPAm/MAA) Nanoparticles With Proteins and Cells," J. Biomater. Sci. Polymer Edn. 11(2):123-147, 2000.
Nakajima, K., et al., "Intact Microglia are Cultured and Non-Invasively Harvested Without Pathological Activation Using a Novel Cultured Cell Recovery Method," Biomaterials 22(11):1213-1223, 2001.
Nakayama, Y., and T. Matsuda, "Surface Macromolecular Microarchitecture Design: Biocompatible Surfaces via Photo-Block-Graft-Copolymerization Using N,N-Diethyldithiocarbamate," Langmuir 15(17):5560-5566, 1999.
Nath, N., and A. Chilkoti, "Fabrication of a Reversible Protein Array Directly From Cell Lysate Using a Stimuli-Responsive Polypeptide," Anal. Chem. 75(4):709-715, Feb. 15, 2003.
Ng, J.H., and L.L. Ilag, "Biomedical Applications of Protein Chips," J. Cell. Mol. Med. 6(3):329-340, 2002.
Okamura, H., et al., "A Novel Thermosensitive Polymer, Poly(Methyl 2-Propionamidoacrylate), With Geminal Substituents," Polymer 43(13):3825-3828, 2002.
Okano, T., et al., "Temperature-Responsive Poly(N-Isopropylacrylamide) as a Modulator for Alteration of Hydrophilic Hydrophobic Surface Properties to Control Activation/Inactivation of Platelets," J. Control. Release 36:125-133, 1995.
Pan, Y.V., et al., "Plasma Polymerized N-Isopropylacrylamide: Synthesis and Characterization of a Smart Thermally Responsive Coating," Biomacromolecules 2(1):32-36, 2001.
Park, S.Y., et al., "Characterization of Temperature-Induced Phase Transition of Polymer Complex Composed of Poly-(N,N-Dimethylamino)ethyl Methacrylate and Poly(Ethyacrylamide) by <SUP>1</SUP>H-1-NMR Relaxation Time Measurement," European Polymer Journal 37(9):1785-1790, 2001.
Park, Y.S., and Y. Ito, "Micropattern-Immobilization of Heparin to Regulate Cell Growth With Fibroblast Growth Factor," Cytotechnology 33:117-122, 2000.
Persson, J., et al., "Polymer Recycling in Aqueous Two-Phase Extractions Using Thermoseparating Ethylene Oxide-Propylene Oxide Copolymers," Journal of Chromatography B 743(1-2):115-126, 2000.
Pettit, D.K., et al., "Influence of the Substrate Binding Characteristics of Fibronectin on Corneal Epithelial Cell Outgrowth," J. Biomed. Mater. Res. 26(10):1259-1275, Oct. 1992.
Priest, J.H., et al., Lower Critical Solution Temperatures of Aqueous Co-polymers of N-Isopropylacrylamide and Other N-Substituted Acrylamides, ACS Symposium Series 350, New York, New York, Apr. 13-18, 1986, pp. 255-264.
Sanford, M.S., et al., "Photoactivatable Cross-Linked Polyacrylamide for the Site-Selective Immobilization of Antigens and Antibodies," Chem. Mater. 10(6):1510-1520, 1998.
Schakenraad, J.M., et al., "The Influence of Substratum Surface Free Energy on Growth and Spreading of Human Fibroblasts in the Presence and Absence of Serum-Proteins," J. Biomed. Mater. Res. 20(6):773-784, Jul./Aug. 1986.
Shimizu, T., et al., "Two-Dimensional Manipulation of Cardiac Myocyte Sheets Utilizing Temperature-Responsive Culture Dishes Augments the Pulsatile Amplitude," Tissue Engineering 7(2):141-151, 2001.
Sigal, G.B., et al., "Effect of Surface Wettability on the Adsorption of Proteins and Detergents," J. Am. Chem. Soc. 120(14):3464-3473, 1998.
Sugiyama, K., et al., "Preparation and Application of Chiral Recognizable Thermosensitive Polymers and Hydrogels Consisting of N-Methacryloyl-s-Phenylalanine Methyl Ester," J. Appl. Polym. Sci. 82(1):228-236, 2001.
Takada, M., et al., "Interaction Parameters of Poly(Vinyl Methyl-Ether) in 2-Propanol Water Mixture as Determined by Small-Angle Neutron- Scattering," Kobunshi Ronbunshu 51(11):689-693, 1994. [Abstract].
Takahashi, M., et al., "Thermoreversible Gelation and Phase Separation in Aqueous Methyl Cellulose Solutions," J. Polym. Sci. Part B: Polym. Phys. 39(1):91-100, 2001.
Takei et al. "Dynamic Contact Angle Measurement of Temperature-Responsive Surface Properties for Poly(N-isopropylacrylamide) Grafted Surfaces", Marcomolecules 1994, 27, 6163-6166. *
Terada, T., et al., "Raman Spectroscopic Study on Water in Aqueous Solutions of Temperature-Responsive Polymers: Poly(N-Isopropylacrylamide) and Poly[N-(3-Ethoxypropyl)Acrylamide]," Macromol. Chem. Phys. 195(9):3261-3270, Sep. 1994.
Welin-Klintström, S., et al., "Surfactant and Protein Interactions on Wettability Gradient Surfaces," J. Colloid Interface Sci. 158:188-194, 1993.
Williams, D.F. (ed.), Techniques of Biocompatibility Testing, vol. II, CRC Press, Boca Raton, Florida, 1986, Chap. 9, "Techniques for Protein Adsorption Studies," pp. 184-212.
Wright, E.R., and V.P. Conticello, "Self-Assembly of Block Copolymers Derived From Elastin-Mimetic Polypeptide Sequences," Advanced Drug Delivery Reviews 54(8):1057-1073, 2002.
Wu, R.Z., et al., "Cell-Biological Applications of Transfected-Cell Microarrays," Trends Cell Biol. 12(10):485-488, Oct. 2002.
Xiong, X., et al., "Controlled Multibatch Self-Assembly of Microdevices," J. Microelectromech. Sys. 12(2):117-127, Apr. 2003.
Yamada, N., et al., Makromolekulare Chemie, Rapid Communciations 11(11):571-576, Nov. 1990.
Yamato, M., et al., "Novel Patterned Cell Coculture Utilizing Thermally Responsive Grafted Polymer Surfaces," J. Biomed. Mater. Res. 55(1):137-140, Apr. 2001.
Yamato, M., et al., "Release of Adsorbed Fibronectin From Temperature-Responsive Culture Surfaces Requires Cellular Activity," Biomaterials 21:981-986, 2000.
Yamato, M., et al., "Thermo-Responsive Culture Dishes Allow the Intact Harvest of Multilayered Keratinocyte Sheets Without Dispase by Reducing Temperature," Tissue Engineering 7(4):473-480, 2001.
Yousaf, M.N., et al., "Using Electroactive Substrates to Pattern the Attachment of Two Different Cell Populations," Proc. Natl. Acad. Sci. US A 98(11):5992-5996, May 22, 2001.
Zhong, Y.Z., and P. Wolf, "Effects of Hydrophobic Unit and Its Distribution on Solution Properties of Vinyl Pyrrolidone and Vinyl Acetate Copolymer," J. Appl. Polym. Sci. 74(2):345-352, 1999.

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080160559A1 (en) * 2006-06-12 2008-07-03 Carre Alain R E Thermo-responsive blends and uses thereof
US9090930B2 (en) 2006-06-27 2015-07-28 Emd Millipore Corporation Method and unit for preparing a sample for the microbiological analysis of a liquid
US9410181B2 (en) 2006-06-27 2016-08-09 Emd Millipore Corporation Method and unit for preparing a sample for the microbiological analysis of a liquid
US8163886B2 (en) 2006-12-21 2012-04-24 Emd Millipore Corporation Purification of proteins
US8362217B2 (en) 2006-12-21 2013-01-29 Emd Millipore Corporation Purification of proteins
US10793593B2 (en) 2006-12-21 2020-10-06 Emd Millipore Corporation Purification of proteins
US8569464B2 (en) 2006-12-21 2013-10-29 Emd Millipore Corporation Purification of proteins
US10233211B2 (en) 2006-12-21 2019-03-19 Emd Millipore Corporation Purification of proteins
US9376464B2 (en) 2006-12-21 2016-06-28 Emd Millipore Corporation Purification of proteins
US8999702B2 (en) 2008-06-11 2015-04-07 Emd Millipore Corporation Stirred tank bioreactor
US9803165B2 (en) 2008-12-16 2017-10-31 Emd Millipore Corporation Stirred tank reactor and method
US8691918B2 (en) 2010-05-17 2014-04-08 Emd Millipore Corporation Stimulus responsive polymers for the purification of biomolecules
US9731288B2 (en) 2010-05-17 2017-08-15 Emd Millipore Corporation Stimulus responsive polymers for the purification of biomolecules
US9217048B2 (en) 2010-05-17 2015-12-22 Emd Millipore Corporation Stimulus responsive polymers for the purification of biomolecules
US9541480B2 (en) 2011-06-29 2017-01-10 Academia Sinica Capture, purification, and release of biological substances using a surface coating
US11674958B2 (en) 2011-06-29 2023-06-13 Academia Sinica Capture, purification, and release of biological substances using a surface coating
US9447239B2 (en) * 2012-03-19 2016-09-20 Samsung Electronics Co., Ltd. Thermosensitive copolymers, forward osmosis water treatment devices including the same, and methods of producing and using the same
US20130240444A1 (en) * 2012-03-19 2013-09-19 Samsung Electronics Co., Ltd. Thermosensitive copolymers, forward osmosis water treatment devices including the same, and methods of producing and using the same
US10495644B2 (en) 2014-04-01 2019-12-03 Academia Sinica Methods and systems for cancer diagnosis and prognosis
US10112198B2 (en) 2014-08-26 2018-10-30 Academia Sinica Collector architecture layout design
US10167546B2 (en) * 2015-04-29 2019-01-01 3M Innovative Properties Company Swellable film forming compositions and methods of nanoimprint lithography employing same
US10107726B2 (en) 2016-03-16 2018-10-23 Cellmax, Ltd. Collection of suspended cells using a transferable membrane
US10605708B2 (en) 2016-03-16 2020-03-31 Cellmax, Ltd Collection of suspended cells using a transferable membrane

Also Published As

Publication number Publication date
WO2004011669A2 (fr) 2004-02-05
AU2003259289A1 (en) 2004-02-16
US20040053334A1 (en) 2004-03-18
WO2004011669A3 (fr) 2004-06-10

Similar Documents

Publication Publication Date Title
US7442515B2 (en) Apparatus and methods for binding molecules and cells
Cheng et al. Novel cell patterning using microheater‐controlled thermoresponsive plasma films
Chandra Programmable cell adhesion encoded by DNA hybridization
US10725021B2 (en) Muscle chips and methods of use thereof
Hsiao et al. Direct cell surface modification with DNA for the capture of primary cells and the investigation of myotube formation on defined patterns
US10753925B2 (en) Devices comprising muscle thin films and uses thereof in high throughput assays for determining contractile function
JP4479960B2 (ja) 細胞中へのタンパク質送達のための方法および器具
Folch et al. Microengineering of cellular interactions
JP4822753B2 (ja) 細胞構成物質分取チップならびに細胞構成物質解析システム及びこれらを用いる細胞構成物質解析法
Turcu et al. Ink-jet printing for micropattern generation of laminin for neuronal adhesion
WO2008108004A1 (fr) Puce d&#39;échantillonnage d&#39;un composant de cellule, système d&#39;analyse d&#39;un composant de cellule et procédé d&#39;analyse d&#39;un composant de cellule au moyen de celui-ci
US20260008051A1 (en) Microfluidic Device for Live Cell Manipulation and Analysis
Yamazoe et al. Cell micropatterning on an albumin‐based substrate using an inkjet printing technique
US20060105350A1 (en) Method and system for sorting and separating particles
US20060183166A1 (en) Arrays of supported biomembranes and uses thereof
Quist et al. Micropatterned surfaces: techniques and applications in cell biology
JP2008054511A (ja) 複数細胞固定用装置および細胞固定化方法
CN101218028A (zh) 用于高通量筛选的细胞基平台
JP4328533B2 (ja) 複数の生体分子を規定の比率にて表面に共に固定化する方法及び同方法により形成された表面
von Philipsborn et al. Substrate-bound protein gradients for cell culture fabricated by microfluidic networks and microcontact printing
KR102926336B1 (ko) 마이크로 구조체 및 분자 검출 방법
Hsiao DNA-cell conjugates and cellular biophysical studies using AFM
WO2022220844A1 (fr) Dispositifs de dosage pour bibliothèques combinatoires

Legal Events

Date Code Title Description
AS Assignment

Owner name: WASHINGTON, UNIVERSITY OF, WASHINGTON

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:RATNER, BUDDY D.;CHENG, XUANHONG;BOHRINGER, KARL;AND OTHERS;REEL/FRAME:014124/0903;SIGNING DATES FROM 20030903 TO 20031001

STCF Information on status: patent grant

Free format text: PATENTED CASE

CC Certificate of correction
FPAY Fee payment

Year of fee payment: 4

FPAY Fee payment

Year of fee payment: 8

FEPP Fee payment procedure

Free format text: MAINTENANCE FEE REMINDER MAILED (ORIGINAL EVENT CODE: REM.); ENTITY STATUS OF PATENT OWNER: SMALL ENTITY

LAPS Lapse for failure to pay maintenance fees

Free format text: PATENT EXPIRED FOR FAILURE TO PAY MAINTENANCE FEES (ORIGINAL EVENT CODE: EXP.); ENTITY STATUS OF PATENT OWNER: SMALL ENTITY

STCH Information on status: patent discontinuation

Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362

FP Lapsed due to failure to pay maintenance fee

Effective date: 20201028